For most of us, democratic responsibilities begin and end with voting. We make choices between incumbents and new candidates, staying the course or trying new directions. But American democracy depends on another form of civic participation, too: running for office.

According to the U.S. Census Bureau, there are more than 500,000 elected public offices in the United States. Relatively little is known about who runs for these offices, so the Cooperative Congressional Election Study polled its sample of 55,000 adult citizens to find out more.

We found that three out of every one hundred adults, approximately six million people, have run for office at some point in their lives. The typical American who runs for office is not a career politician in the state legislature or Congress. Most (78 percent) run only once, and a great majority (85 percent) run only for local office, such as school committee, city council, or mayor.

The candidates show distinct demographic trends, differentiating them from the population as a whole. Men are twice as likely as women to run for office. People with post-graduate education are three times as likely to run for office as people with a high school degree or less. Those who make more than $100,000 a year are almost twice as likely to run for public office as those who make less than $50,000 a year.

Americans run for office in late middle age. Just 2 percent of 18–54 year-olds say they have run for public office. Between the ages of 55 and 65, civic spirit soars, as 4.5 percent report running for office. Among those over 65, the figure rises to 5.3 percent.

Interestingly, there is less racial disparity. Three percent of whites report that they have run for office, compared with 2 percent of African Americans and 2 percent of Hispanics.

What about political differences between candidates and the rest of the public? There is a conservative tilt to the pool of candidates: the median ideology of candidates is “slightly conservative,” while the median ideology of non-candidates is “moderate.” More striking than the disconnect between candidates and non-candidates, however, is the distribution across the political spectrum. Those who describe themselves as very conservative or very liberal are two and a half times more likely to run for office than are those who consider themselves moderates.

So the choices we face are disproportionately at the poles, even in elections for school committee and city council. That the pool of candidates is disproportionately outside the center may contribute to the widely held sentiment that U.S. politics is highly polarized.

Differences aside, the numbers point to an even bigger concern: a shortage of candidates. Since most candidates run only once, and the age window for campaigning, in practice, is brief, we run out of candidates more quickly than new ones appear. The resulting scarcity of candidates is most visible below the federal level. Almost half of state-legislative elections are uncontested, and local elections seem to be equally poorly contested, although a hard count is not available.

Americans readily seize on elections as a political solution to matters of public concern. But our embrace of democratic politics seems to have reached a limit when it comes to willingness to stand for election. And the sorts of people who do run for office at the local level create some of the imbalances in our polity—dominated by well-educated, high-income men whose political views are not widely shared. The expansion of democracy rests, then, on the expansion of democratic practice. Don’t just vote, in other words: run for office.

And if you run, don’t be shy about passing the hat. As the examples from Massachusetts show, even a local election requires a hefty investment.